Micronuclei and their association with sperm abnormalities, infertility, pregnancy loss, pre-eclampsia and intra-uterine growth restriction in humans

The micronucleus (MN) assay is increasingly being used to study the association between DNA damage and infertility or pregnancy complications in humans. This review provides a brief overview of the studies published to date. The results of these studies appear to support the plausibility of the following hypotheses: (i) MN in spermatids in semen may be indicative of infertility risk, (ii) MN in peripheral blood lymphocytes in males correlate positively with DNA damage in sperm, (iii) infertile couples exhibit higher frequencies of MN than fertile couples and (iv) an abnormally high frequency of MN in peripheral blood lymphocytes is associated with pregnancy complications including miscarriage, intra-uterine growth restriction and pre-eclampsia. The studies published to date consistently indicate an association of MN in peripheral blood lymphocytes with impaired reproductive capacity. However, the conclusions of these studies, although statistically significant, are limited by small sample sizes and the need for verification in other independent cohorts. In conclusion, more attention should be given to the possibility of using MN assays in peripheral blood lymphocytes and reproductive tissues as a biomarker of risk for infertility and pregnancy complications in humans.